What is Built Up Roofing? (BUR)

BUR is a petroleum-based roofing system where mastics are heated to a liquid state and applied to felt rolled out on the roof substrate. Multiple layers are laid until the system is built up to the desired thickness.

Built Up Roofing System Problems


Any petroleum based roofing system is continuously curing, which means the solvents that keep it pliable are continually evaporating. Exposure to ponding water and UV radiation accelerate this process. When the solvents are evaporated, the layers begin to delaminate causing the system to shrink, crack, and blister.


With a BUR roof, the curing process starts from the top down. As the solvents evaporate, the material loses mass and shrinks. This causes cracks to form over large parts of the roof. They are small at first but continue to grow, and eventually, travel all the way through the roof.

Transitions between roofing materials

Penetration flashings are problematic with a built-up roofing system. This is primarily due to the use of rigid and dissimilar materials to make this critical transition. As the mastic that is used to seal the seams in the BUR ages, it loses its ability to absorb movement and is pulled apart.

The same forces that act to destroy the penetration flashings affect the edge detail as well. Most seams where the BUR meets the edge metal tend to pull apart. Repairs involve applying additional mastic to the deficiency, but if repairs are unsuccessful, the edge detail is ineffective.

Seams between the individual pieces of parapet flashing tend to pull apart. Once open to the elements repairs often begin to crack again. The same forces that act to destroy the penetration flashings are also at work on the parapet flashings.

BUR Roof Repairs

Repairs to built up roofs involve applying additional mastic to each deficiency area. After multiple repairs, the longevity of each subsequent repair is shorter and shorter.

Our Best Recommendation

For a permanent, warranted solution, we recommend installing a complete mechanically-fastened Springfield SmartRoof™ System.

The Springfield SmartRoof™ System is entirely maintenance free.* Certified Springfield technicians will install this system, and completed in strict accordance with the manufacturer’s specifications. It will be 100% inspected by the Springfield Team, and then by an inspector from the manufacturer. The manufacturer will then award a full 20-year warranty, which is the best on the market.

Springfield Smart Roof*Annual inspections and debris removal are recommended and included at no charge for the first two years of your roof’s life. These inspections help us track the performance of your roofing system and also keep abreast of any new developments that could occur over time. Please contact your Project Manager to schedule your inspections.

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